Blue smoke on startup.

[jwatkins]

My 97, 155,000 miles, has blue smoke on startup at any temp below 50. It is not a lot just a light haze. It's been like this for about a year and a half. There is no excessive oil comsumption, only about a 1/2 qt. Every 5k miles. When I changed the fuel filter it was black so I am assuming that means that there is some injector orings that are leaking. When I smell the exhaust it is a very strong diesel smell and I can't smell any oil. My question, is can a worn out injector or two cause it to have blue smoke?

It has also seemed to have lost power and has lost about 4mpg since I bought it a couple years ago.

[jwatkins]

Forgot to add that there is also quite a bit of white smoke on start-up. Also there is a slight hesitation around 2300rpm when reving it with the chip in the stock position or with the chip out. If I turn the chip on it goes away. The truck fires right up even when below freezing, within two seconds.
Thanks,
Jared

[jwatkins]

Anybody?

[BigFuel]

Hey,

The blue smoke normally presents itself because the cylinders are cold and no matter how many times you cycle the GP the metal of the cylinders will remain pretty cold until the engine is running. Mine will do this, also, anytime it is below 45-50 at night for the first start of the day. It is normally just incomplete combustion for several minutes then once things warm up it goes away. Plugging in the truck for a couple hours before you want to leave will get rid of most of it but starting the motor and letting it idle for 5-10 minutes does the same as long as she's not hard to start.

The flip side of this is that with your other issue (assuming they are related) points to a weak HPOP. In the performance settings the chip will close off the IPR more then the PCM would do on it's own and thus artificially (as in "not how Ford designed it") raise the running pressure of the HPOP and it's produced oil pressure and your injectors run better.

The fuel filter _may_ be pointing at a blown injector O-Ring but that issue typically blows in the other direction, towards the head and not mixing the two fluids. Not saying that is what is happening, just what it normally does. The black fuel filter would normally lead me to a water saturated filter. The filter does its' best to block the water that might be in the fuel but it's last line of defense is to just absorb it. Is the fuel sitting in the bowl clear? or murky/dark?

[jwatkins]

First of all thanks for the reply.

In regards to the fuel, ever since I bought the truck, I have changed the fuel filter at every oil change. I drain the fuel into a clear container and inspect the fuel and filter. The fuel that I have always have gotten is very good quality. The last couple of times that I have changed the filter it has been black and the fuel has had what looks to be soot from oil. At first look the fuel looks good but has a slightly darker tint then brand new fuel.

About the HPOP, I never thought about the chip increasing the pressure and covering the hesitation. If I rev it in neutral it is most noticeable but it is barely noticeable while driving. A normal person would not feel it, but I drive and work on Peterbilts every day, so I learned to feel when something is off.

[BigFuel]

Awesome, so you know your stuff around diesels. The only thing the is not the same with every other truck on the road is the injection system on our 7.3L's. I will concede that you are probably right and there is at least one injector that is passing oil. Do you have an infrared heat gun? At idle and cold start shoot each port on the manifold (after a couple minutes of running to stabilize the warm up of the manifold) and see if there is a cylinder that is cooler then the rest or MUCH hotter then the rest. That will give you a good direction of which cylinder isn't burning right. Pop that side of the motors' valve cover and watch the tops of the injectors. The injectors have a relief/exhaust port for the HP oil after the injectors fired. That one injector should also show less oil coming from that port as apposed to the rest on that side. There is not nearly as much oil moving around inside the head as compared to a Gasser and seeing the problem is pretty easy.

[EDIT] It's more money but if you are popping valve covers might as well do glowplugs and harnesses at the same time.

I love this guys videos:

FORD 7.3L DIESEL #8 FUEL INJECTOR - YouTube

FORD 7.3L DIESEL #8 FUEL INJECTOR - YouTube

[jwatkins]

Thanks for all of the help. Yes I have a inferred thermometer, I’ve checked each cylinder while warm and all were fairly close but I haven’t checked them while there cold.

There is a shop just down from ours that just got some diagnostics stuff that I might be able to use. They normally charge $40 just to read DTCs but the owner used to work for us, so maybe I can luck out and get some tests done for free.

[Diesel_brad]

Loss of power and fuel milage drop can be a dirty air filter

[jwatkins]

Sorry, I should have posted a little more info.

New 6637 air filter
Aprox. 1500 miles on oil and fuel filter
New international cps. (Grey)
I've tried unplugging icp. (Actually seems to run worse)
Cleaned ebs tube, sensor and manifold fitting.
Cleaned fpr screen
Fuel pressure is at 55psi
Ccv mod and no low spots.
Unplugged MAP and didn't notice any difference except stock had a little bit more power.

[jwatkins]

The other day I pulled the driver side valve cover off. I didn’t have the time to do both sides so I chose to do the easy side first. I started it with the VC off, all 4 were shooting oil out but #6 might have been a little less but no significant difference.

Here is the temps of each cylinder at the manifold after 5 minutes of idling.
#2 120*
#4 136*
#6 144*
#8 143*

#1 115*
#3 128*
#5 128*
#7 118*

Here is a video off blue smoke after idling for 15 minutes
VIDEO0028.mp4 video by Jared_Watkins | Photobucket

Also another video if the hesitation and blue smoke in the stoke position After getting it up the operating temp.
VIDEO0029.mp4 video by Jared_Watkins | Photobucket

I going to try to get to the passenger side this week to check them. Also going to rig up a fuel pressure gauge to I can watch it in a hard run. I haven’t been able to get it over to my buddies to run any tests yet because he is swamped.

Also I have noticed if I push it to ¾ throttle from around 1200rpms with the chip in the highest setting it seems to kind of makes a crackle sound from the exhaust and hesitates or sputters, Around 1900 if you back out to about 1/2 throttle it seems to have more power. Once you get over 2000 it everything feels feels normal. Do you think this is part of my problem or is it something else